Automatic lock slider for slide fasteners



/Nl//V70E Gideon Suzzdback March 11, 1952 5. SUNDBACK AUTOMATIC LOCKSLIDER FOR SLIDE FASTENERS Filed Aug. 5, 1946 Fig.5

Patented Mar. 11, 1952 AUTOMATIC LOCK SLIDER FOR SLIDE FASTENERS GideonSundback, Meadville, Pa., assignor to Talon, Inc., Meadville, Pa., acorporation of Pennsylvania Application August 3, 1946, Serial No.688,213

This invention relates to an automatic lock slider for slide fasteners.It is customary to provide slide fasteners with a slider which isnormally and automatically locked to the chain or stringers to preventunintended opening of the fastener, but which is freely movable eitherto close the zipper or to accomplish intended opening of the fastener.Such sliders usually have a spring-pressed locking point or prongnormally held in looking position, blocking the channel in the sliderthrough which the interlocking elements pass. The prong is automaticallyremoved from locking position against the force of the spring wheneverthe customary handle or pull tab is pulled in the direction tending toopen the fastener.

Such known slide fasteners are satisfactory within their inherentlimitations, but have several disadvantages. They depend upon the forceof the spring to effect locking. Therefore if the slider locks securely,a strong spring is required. Such a spring constantly urges the lockingprong so firmly against the interlocking elements of the chain that whenthe fastener is closed, the prong ratchets roughly over the interlockingelements. This has several undesirable results. It is objectionablynoisy. It makes the slider rough to operate. The prong wears on theinterlocking element and rapidly wears out its locking point. When usedwith colored fasteners, the point also removes the paint or chemicalfinish from the interlocking elements. On the other hand if it is soughtto eliminate these disadvantages by using a light spring, the lockingaction is uncertain and insecure.

One of the objects of the present invention is slider which is certainand secure in its locking action, and in which ratcheting when closingthe fastener is greatly reduced or substantially eliminated. Morespecifically it is an object to provide alocking member which isnormally held in an incipient or potential locking position and is movedautomatically to locking position whenever the slider tends to open thefastener without opening action of the pull tab.

Another object is to provide an improved form of locking means whichengages opposite sides of an interlocking element, as distinguished fromthe usual locking element which engages only one side.

Another object is to provide 'animproved form of lock slider which willbe economical to manufacture and which will have along locking life, itbeing the fault of many locking sliders that 12 Claims. (01. 24-20514)they soon lose their locking characteristics even though they remainserviceable as non-locking sliders.

Still another object is to provide an improved form of locking elementparticularly suitable for use in die-cast sliders and which can bereadily and cheaply assembled in a die-cast slider body after completionof the casting operation.

Another object is to provide an improved lock slider in which thelocking force increases with increasing force tending to open thefastener.

In the accompanying drawings:

Fig. 1 is a perspective view of a slide embodying one form of myinvention;

Fig. 2 is an elevation of the bottom end of the slider shown in Fig. 1,drawn on an enlarged scale;

Fig. 3 is a section of the slider on the line 33 fastener of Fig. 2showing the locking parts of the slider in their normal or neutralposition; i

Fig. 4 is a similar section showing the locking parts in lockedposition; and

Fig. 5 is a, similar section showing the locking parts in unlockedposition. 1

Referring to the drawings, the slide fastener consists of a pair ofstringers or chains: each including a fabric tape III, to one edge ofwhich is secured a row of interlocking elements I2. The fastener isopened or closed by a slider 14 which embraces both rows of interlockingelements and has a Y-shaped channel 16 (Fig. 2) for the passage ofelements through it, a pair of cam faces 18 (Fig. 1) for progressivelyinterlocking the elements when the slider is moved in one direction, anda diamond or wedge 20 for progressively disengaging the elements to openthe fastener when the slider is moved in the opposite direction.

The tapes may be permanently secured together at the lower or closed endof the fastener by a. connecting clip 22, called a bottom stop. Theslider body is provided with a bail or loop 24 to which is attached apull tab 26 for moving the slider along the tapes. The slider body,including the ball, is preferably diecast as an integral piece includingan upper face or plate 21, a lower plate 28, and a connecting wedge ordiamond 20. As so far described the fastener is well known. It is alsoknown to provide various forms of locking devices which automaticallyprevent unintended opening of the fastener by locking the slider to thechain except when the slider is operated by thepull, in which case it isautomaticallyunlocked.

In accordance with my invention I provide an improved locking meansincluding members projecting into the passage 16 from opposite sides,

blocking passage of the interlocking elements and engaging one or moreelements on opposite sides simultaneously. The locking members arenormally disposed in a neutral position and are automatically moved intolocking position whenever any force other than that exerted by the pull26 tends to move the slider in the opening direction.

A preferred form of construction for accomplishing this is thefollowing. A longitudinal slot 30 is formed in'the slider body,extending through one end of the bail, entirely through a part of theupper plate 21, through the point of the diamond and part way through aportion of the lower plate 28. This forms a slot in the upper plate anda groove in the lower plate, which function as longitudinal guidewaysfor spring arms 36 and 31 carrying locking prongs 39 and 40. Preferablythe spring arms are opposite ends or forks of a Y- ,Shaped spring member4! which has a tail 42 slidably mounted in a third longitudinal guideway43 drilled or cast in the diamond. The entire spring member is so formedand disposed that the locking points 39 and normally just touch oppositesides of an interlocking element asindicated in Fig. 3. This is aneutral position, neither locked nor entirely free, but the prongs areheld in an incipient 01' potential locking position from which they aremoved to locked position whenever the slider tends to move in the openindie rection otherwise thanunder the force of the pull tab. The end ofthe arm 36 is formed into a hook 44 lying generally within the end ofthe bail but normally projecting inside the loop as shown in Fig, 3and'shaped to conform to this portion of the'bail. As shown best in Fig.3, the part of the slot 30 located in the bail terminates in a slopingsurface forming a cam face 45 designed to cooperate with the end of thehook 44 which has a surface parallel to the cam surface and adjacent toit, so that when the slider body is moved to the right as seen in Fig. 4and the lockin 'sprin is held stationary, the cam face urges the springarm'and its locking point 39 toward the interlocking elements. The freeend of the opposite spring arm 3! is formed with an inclined tip 41which projects into an inclined hole through the lower face plate 28 ofthe slider body. One side 48 of thisghole acts as a cam face which, whenthe slider body is slid to'the right and the sprin arm held stationary,as seen in Fig. 4, forces the locking point 40 toward the interlockingelements. The other side 5.9 of the inclined hole acts as a cam facewhich, when the spring arm is moved to the right withrespect to theslider body as seen in Fig. .5, moves the locking point 40 out ofengagement with the interlocking elements and out of .thejslider passageI8. I

The slider is normally as shown in Fig. 3. The locking points .39 and 40engage the opposite sides .of the interlocking elements withinsufficient force to cause secure looking action, but with just enoughforce to hold the lockin spring stationary on the chain ii the slidertends to move to the right as seen in Fig. 3, in any opening movementother than that caused by the pull tab. When this occurs, the cam faces45 and 48 press the locking prongs into the channel it between theinterlocking elements as shown in Fig. 4, and lock the slider byblocking passage of the elements through the slider. It will be observedthat the force tending to move the slider in the opening direction isincreased, the cam faces increase the force with which the lockingpoints are held in contact with the interlocking elements, thusincreasing security of the locking action in proportion to the openingforce. When the pressure on the slider tending to open the fastener isreleased, or when the Y-spring is moved to the right with respect to theslider body as seen in Fig. 5, the arms with their locking prongs 39 and49 under spring tension lift away from the interlocking elements intoneutral position as shown in Fig. 3. Whenever the fastener is opened bythe pull, the pull occupies the position shown in Fig. 5, the forcealong the pull having a transverse component represented by the vector52 and a longitudinal component which is represented by the vector 54.The transverse component flexes the arm 36 and moves the locking member39 out of engagement with the interlocking elements and entirely out of.the passage IS. 'The longitudinal component slides the spring member 4!to the right from the position shown in Fig. 4 to the position shown inFig.5. As this occurs the spring arm 31 is flexed by the camfill to movethe locking prong 40 out of the slider passage. When the hook '44 hasbeen pushed into the loop far enough to lift the "prongs 3 9 and 40 outof contact with the interlocking-elements the pull tab engages the loopto move the slider. If desired each spring arm may carry a pair oflocking prongs 39 or 40 which simultaneously engage a pair ofinterlocking elements 12, thus enhancing the security of the-lockingaction and prolonging the life of the locking members.

When it is desired to close the fastener, the pull is operated in theposition .shown in Fig. 1, where it draws the slider in the direction toclose the fastener, leaving the locking spring .free. Since the lockingelement is in the position shown in Fig. '3, the locking points canslide over the interlocking elements, alternately movin between thepositions shown in Fig. ,3 and Fig. '5. Due to the fact that thepressure on the elements is very light, .even with the locking points inthe position shown in Fig. 5, ratcheting is very light and does notremove the finish from the elements or cause rough operation of theslider.

In practice the slider body may have the slot 30 and guide hole 43formed by cores or projections in the die in which it is cast, and theslanting hole forming the cam 48 and '50 may either be cored or may bepierced in the finished casting. The spring member 4| may be stamped outof spring material. It is inserted in the finished slider body bysliding it into the open end of the slot, the arm 3'! being flexedsufiiciently to let the inclined end '41 enter the slot '30. Theinclined end snaps into the slanting hole, permanently retaining thespring in the slider body.

Thus the slider has a pair of looking members which engage oppositefaces of an'interlocking element, the pull disengages one lookingelement fromthe row of interlocking elements and moves it out of theslider passage, simultaneouslocking member 40 more firmly against thein- ,terlocking elements I2 instead of removing it from them. Howeverthe guiding tail 42 may not be necessary in all cases, and in someinstances I may omit it.

I claim:

1. A slide fastener comprising in combination, a pair of rows ofinterlocking elements, a slider having a passage for the rows andadapted when moved in one direction along the rows to interlock the rowstoclose the fastener and when moved in the opposite directionalong therows to disengage the rows to open the fastener, a locking membermovable longitudinally in the slider and adapted to project into thepassage, means carried by the slider resiliently holding the lockingmember in a fixed position projecting into the path of the interlockingelements through the passage, and means responsive to engagement of aninterlocking element with the locking member and subsequent longitudinalmovement of the slider along the rows in the opening direction formoving the locking member further into said path.

2. A slide fastener comprising in combination, a pair of rows ofinterlocking elements, a slider having a passage for the rows andadapted when moved in one direction along the rows to interlock the rowsto close the fastener and when moved in the opposite direction along therows to disengage the rows to open the fastener, a locking membermovable longitudinally in the slider and adapted to project into thepassage, means carried by the slider resiliently holding the lockingmember in a fixed position projecting into the path of. the interlockingelements through the passage and an inclined cam for moving the lockingmember further into the said path in response to engagement of anelement with the locking member and to subsequent longitudinal movementof the slider with respect to the locking member in the openingdirection.

3. A slide fastener comprising in combination a pair of rows ofinterlocking elements, a slider having a passage for the rows andadapted when moved in one direction along the rows to interlock the rowsto close the fastener, and when moved in the opposite direction alongthe rows to disengage the rows to open the fastener, a locking membermovable longitudinally in the ing the locking member further into saidpath in response to engagement of an element with the locking member andto subsequent longitudinal movement of the locking member in onedirection in the slider, means for moving the locking member in theopposite direction in the slider and a second inclined cam for movingthe locking member out of said path in response to movement of thelocking member in the opposite direction.

5. A slide fastener comprising in combination a pair of rows ofinterlocking elements, a slider having a passage for the rows andadapted when moved in one direction along the rows to interlock the rowsto close the fastener, and when moved in the opposite direction alongthe rows to disengage the rows to open the fastener, a locking membermovable longitudinally in the slider and adapted to project into thepassage, means carried by the slider resiliently holding the lockingmember in a fixed position projecting into the path of the interlockingelements through the passage, means responsive to engagement of anelement with the locking member and to subsequenglongitudinal movementof the locking member in one direction in the slider for moving thelocking member further into said path, means for moving the lockingmember in the opposite direction in the slider, means responsive tolongitudinal movement of the looking member in the opposite directionfor moving the locking member out of said path, and a pull tab on theslider for moving the slider in the opening and closing directions, thetab being adapted to move the locking member in said opposite directionin the slider when the tab moves the slider in the opening direction.

6. A slide fastener comprising in combination a pair of rows ofinterlocking elements, a slider having a passage for the rows andadapted when moved in one direction to interlock the rows to close thefastener and when moved in the 0pposite direction to disengage the rowsto Open the fastener, a pair of locking members in the slider adapted toproject into the passage from opposite sides, means carried by theslider reslider and adapted to project into the passage,

means carried by the slider resiliently holding the locking member in afixed position projecting into the path of the interlocking elementsthrough the passage, meansresponsive to engagement of an element withthe locking member and to subsequent longitudinal movement of thelocking member in one direction in the slider for moving the lockingmember further into said path, means for moving the locking member inthe opposite direction in the slider, and means responsive tolongitudinal movement of the locking member in the opposite direction inthe slider for moving the locking member out of said path.

4. A slide fastener comprising in combination a pair of rows ofinterlocking elements, a slider having a passage for the rows andadapted when moved in one direction along the rows to interlock the rowsto close the fastener, and when moved in the opposite direction alongthe rows to disengage the rows to open the fastener, a locking membermovable longitudinally in the slider and adapted to project into thepassage, means carried by the slider resiliently holding the lockingmember in a fixed position projecting into the path of the interlockingelements through the passage, and inclined cam for movsiliently holdingthe locking members in a fixed position projecting into the path of theinterlocking elements through the passage, and means responsive toengagement of an interlocking element with the locking member and tosubsequent initial movement of the slider in the opening direction formoving the locking members further into said path.

7. A slide fastener comprising in combination a pair of rows ofinterlocking elements, a slider embracing the rows, a pull tab formoving the slider along the rows either to interlock the rows to closethe fastener or to disengage the rows to open the fastener, lockingmeans in the slider adapted to engage one side of an interlockingelement, second locking means connected. to the first locking means andadapted to engage the other side of the element, both said locking meansbeing normally in the path of the interlocking elements through theslider and being movable longitudinally of the slider, means connectingthe pull tab to the first locking means for moving said first lockingmeans longitudinally of the slider and out of said path, and meansresponsive to longitudinal movement of said locking means for moving thesecond locking means out of said path.

8. A slide fastener comprising in combination a pair of rows ofinterlocking elements, a. slider mbra ing the o s nd having a p ssagehrough the lider or h i e l cking e men s, a-pul for moving the slideralong the rows either to interlock; the rows to close the fastener or toopen the fastener by disengaging the rows, a pair of connected lockingmembers normally extending into the path of the interlocking elementsthrough the slider, said locking members being movable longitudinally ofthe slider and being movable into and out of said path, means connectingthe pull to one of the locking members for moving the memberslongitudinally of the'slider and for moving both of the locking membersout of the passage, and means responsive to longitudinal movement of thelocking members for moving the other locking member out of said path.

9, A slide fastener comprising in combination a pair of rows ofinterlocking elements, a slider embracing the rows and having a passagethrough the slider for the elements, a pull for moving the slider alongthe rows either to interlock the rows to close the fastener or todisengage the rows to open the fastener, locking means in the slideradapted to project into one side of the passage, a' second locking meansconnected to the first locking means and adapted to project into theopposite side of the passage, both looking means extending normally intothe path of the interlocking elements through the slider, meansconnecting the pull to one of the locking means'for moving both lockingmeans longitudinally of the slider and for moving one locking means outof said path, a cam face on the second locking means and a cam on theslider for moving the second locking means out of said path in responseto movement of the locking means longitudinally of the slider,

10. A slide fastener comprising in combination a pair of rows ofinterlocking elements, a slider embracing the rows and having a passagethrough the slider for the elements, a pull for moving the slider alongthe rows either to interlock the rows to close the fastener or todisengage the rows to open the fastener, a spring longitudinally movablein the slider and having a pair of arms ex tending on opposite sides ofsaid passage, a locking member carried by each arm and normallypositioned in the path of the interlocking elements through the passage,means connecting the pull to one arm of the spring for moving the springlongitudinally of the slider and for moving one looking member out ofthe passage, and means cooperating with the other arm of the spring formoving the other locking member out .of the passage in response tolongitudinal movement of the spring.

8 V 11. A slide fastener comprisi g i combin tion a pair of rows ofinterlocking elements, a slider embracing the rows and having a passageextending through the slider for the elements, a longitudinal guide inthe slider, a pull for moving the slider along the rows either tointerlock the rows to close the fastener or to disengage the rows toopen the fastener, a forked member hav-.- ing the tail of the forkslidable in said longitudinal guide and having a pa f es l nt msextending on opposite sides of said passage, a locking member carried byeach arm and normally extending within the passage, means connecting thepull to one of the arms for moving the forked member longitudinally ofthe-slider and for moving one of the locking members out of the passage,and means cooperating with the other arm to move the other lockingmember out of the passage in response to longitudinal movement of theforked member.

12. A slide fastener comprising in combination a pair of rows ofinterlocking elements, a slider embracing the rows and having a passageextending through the slider for the elements, a pair of longitudinalguides in the slider, a pull for moving the slider along the rows eitherto interlock the rows to close the fastener or to disengage the rows toopen the fastener, a resilient arm slidable in one guide, a lockingmember earried'by the arm and normally held by the resilient arm in saidpassage, a second resilient arm connected to the first arm and disposedin the second guide, a second locking member carried by the second armand normally positioned by t se ond a m ithin the pa s g means nectingthe pull to the first arm for moving the first locking member out of thepassage and for sliding the arms in the guides and means responsive tosliding of the arms in the guides for moving the second locking memberout of the passa e.

GIDEON SUNDBACK.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES rATE Ts Numbe N m Da 2,018,948 Corner Oct. 29, 19352,077,360 Gilmore Apr. 13,1937 2,178,949 Brozek Nov. 7; 1939 2,274,723Morin Mar. 3, 1,942

